 | This article needs additional citations for verification .(January 2021) |
The M18 Colored Smoke Grenade is a US Army grenade used as a ground-to-ground or ground-to-air signaling device, a target or landing zone marking device, or a screening device for unit maneuvering.
The M18 was developed in 1942 during World War II and was completed in November of that year. It was designed to replace the M16 smoke grenade, which did not burn as long or as vividly. It was designated standard issue in the fall of 1943. Both were produced at the same time as the M16 production lines were already setup when the M18 was adopted. The M16 was available in red, orange, yellow, green, blue, violet, and black. The M18 initially were going to be produced in the same colors, including white, but it was decided to limit it to four colors (red, yellow, green and violet) for simplicity. The M16 was declared limited standard in 1944 but was still available when it was declared obsolete in the early 1990s.
The violet-colored smoke grenade was used in-theater because of its vivid color; previously it was only used in the United States for training. Its smoke was more toxic than the other color mixtures and was removed from the inventory after the end of the Cold War in the 1990s.
The green-colored smoke grenade was still used in Southeast Asia because the jungle undergrowth was a different color and would still contrast with it. It was discovered that the green smoke drove away swarming bees[ citation needed ].
When a ground element popped smoke to identify its location to aircraft, the aircraft was not told the color, but told to identify the color they saw. This prevented the VC/NVA if monitoring the frequency from popping smoke of the same color to confuse the aircraft. For additional security the colors were sometimes identified as cherry (red), lime (green), lemon or banana (yellow), or grape (violet).
| Model 18 Colored Smoke Grenade | |
|---|---|
| Color/Markings: | Olive drab body with a pale green band and markings, the top painted red, yellow, green, or violet to indicate the smoke color and the color's name marked on the side. In World War II the M18 had a light gray body with a yellow band and markings and the top was in the smoke color. |
| Body: | Sheet steel cylinder with four emission holes at the top and one at the bottom to allow smoke release when the grenade is ignited. |
| Fuze Assembly: | M201A1 Pull-ring Igniter. A "mouse trap" type igniting fuze with a 1.2 to 2.0 second delay. Ignition ignites the filler and expels it from the grenade body. |
| Filler : | 11.5 ounces (326 grams) [1] of a colored smoke mixture. Available in red, green, yellow, or violet. |
| Weight: | 19 ounces (539 grams) [1] |
| Safety clip: | No. |
| Range: | Can be thrown 35 meters (115 ft) by an average soldier. |
| Duration: | The grenade produces a cloud of colored smoke for 50 to 90 seconds (0.85-1.5 minutes). |
With both the white AN-M8 and colored M18 there is a danger of starting a fire if it is used in a dry area. Expended smoke grenade canisters remain hot for some time after burning out and should not be picked up bare-handed.
The smoke is harmful if it is inhaled for prolonged periods; new smoke mixtures are under development that are less toxic. In enclosed spaces the smoke displaces oxygen and can cause respiratory or oxygen deprivation.
Color or colour is the visual perception based on the electromagnetic spectrum. Though color is not an inherent property of matter, color perception is related to an object's light absorption, reflection, emission spectra and interference. For most humans, colors are perceived in the visible light spectrum with three types of cone cells (trichromacy). Other animals may have a different number of cone cell types or have eyes sensitive to different wavelength, such as bees that can distinguish ultraviolet, and thus have a different color sensitivity range. Animal perception of color originates from different light wavelength or spectral sensitivity in cone cell types, which is then processed by the brain.
Magenta is a purplish-red color. On color wheels of the RGB (additive) and CMY (subtractive) color models, it is located precisely midway between red and blue. It is one of the four colors of ink used in color printing by an inkjet printer, along with yellow, cyan, and black to make all other colors. The tone of magenta used in printing, printer's magenta, is redder than the magenta of the RGB (additive) model, the former being closer to rose.
An electronic color code or electronic colour code is used to indicate the values or ratings of electronic components, usually for resistors, but also for capacitors, inductors, diodes and others. A separate code, the 25-pair color code, is used to identify wires in some telecommunications cables. Different codes are used for wire leads on devices such as transformers or in building wiring.
Complementary colors are pairs of colors which, when combined or mixed, cancel each other out by producing a grayscale color like white or black. When placed next to each other, they create the strongest contrast for those two colors. Complementary colors may also be called "opposite colors".
Tracer ammunition (AMO) (Tracers) are bullets or cannon-caliber projectiles that are built with a small pyrotechnic charge in their base. When fired, the pyrotechnic composition is ignited by the burning powder and burns very brightly, making the projectile trajectory visible to the naked eye during daylight, and very bright during nighttime firing. This allows the shooter to visually trace the flight path of the projectile and thus make necessary ballistic corrections, without having to confirm projectile impacts and without even using the sights of the weapon. Tracer fire can also be used as a marking tool to signal other shooters to concentrate their fire on a particular target during battle.
A smoke grenade is a canister-type grenade used as a signaling device, target or landing zone marking device, or as a screening device for unit movements.
In the visual arts, color theory is the body of practical guidance for color mixing and the visual effects of a specific color combination. Color terminology based on the color wheel and its geometry separates colors into primary color, secondary color, and tertiary color. The understanding of color theory dates to antiquity. Aristotle and Claudius Ptolemy already discussed which and how colors can be produced by mixing other colors. The influence of light on color was investigated and revealed further by al-Kindi and Ibn al-Haytham (d.1039). Ibn Sina, Nasir al-Din al-Tusi, and Robert Grosseteste discovered that contrary to the teachings of Aristotle, there are multiple color paths to get from black to white. More modern approaches to color theory principles can be found in the writings of Leone Battista Alberti and the notebooks of Leonardo da Vinci. A formalization of "color theory" began in the 18th century, initially within a partisan controversy over Isaac Newton's theory of color and the nature of primary colors. From there it developed as an independent artistic tradition with only superficial reference to colorimetry and vision science.
Subtractive color or subtractive color mixing predicts the spectral power distribution of light after it passes through successive layers of partially absorbing media. This idealized model is the essential principle of how dyes and pigments are used in color printing and photography, where the perception of color is elicited after white light passes through microscopic "stacks" of partially absorbing media allowing some wavelengths of light to reach the eye and not others, and also in painting, whether the colors are mixed or applied in successive layers.
A Colour wheel or color circle is an abstract illustrative organization of color hues around a circle, which shows the relationships between primary colors, secondary colors, tertiary colors etc.
A smoke screen is smoke released to mask the movement or location of military units such as infantry, tanks, aircraft, or ships.
The military of the United States has used many different types of hand grenades since its foundation.
A tertiary color or intermediate color is a color made by mixing one part of a primary color with half part of another primary, and none of any other primary color, in a given color space such as RGB, CMYK or RYB (traditional).
In chemistry, the CPK coloring is a popular color convention for distinguishing atoms of different chemical elements in molecular models.
Colored smoke is a kind of smoke created by an aerosol of small particles of a suitable pigment or dye.
The AN-M8 HC Smoke Grenade designated as the Army/Navy Model 8 HC Smoke Grenade is a US military grenade used as a ground-to-ground obscuring or screening device or a ground-to-air signaling or target-marking device.
On Vision and Colors is a treatise by Arthur Schopenhauer that was published in May 1816 when the author was 28 years old. Schopenhauer had extensive discussions with Johann Wolfgang von Goethe about the poet's Theory of Colours of 1810, in the months around the turn of the years 1813 and 1814, and initially shared Goethe's views. Their growing theoretical disagreements and Schopenhauer's criticisms made Goethe distance himself from his young collaborator. Although Schopenhauer considered his own theory superior, he would still continue to praise Goethe’s work as an important introduction to his own.
The color magenta has notable tints and shades. These various colors are shown below.
Glass coloring and color marking may be obtained in several ways.
Since the introduction of Crayola drawing crayons by Binney & Smith in 1903, more than two hundred distinctive colors have been produced in a wide variety of assortments. Crayola became such a hit because the company figured out a way to inexpensively combine paraffin wax with safe pigments. The line has undergone several major revisions in its history, notably in 1935, 1949, 1958, and 1990. Numerous specialty crayons have also been produced, complementing the basic Crayola assortment.